Manufacturing method of organic semiconductor film, organic semiconductor film, thin film transistor, active matrix device, electro-optical device, and electronic device

Abstract

A manufacturing method of an organic semiconductor film according to the invention includes applying a liquid composition in which an organic semiconductor material is dissolved or dispersed in a first solvent onto a base material in a predetermined pattern, applying a second solvent in which solubility of the organic semiconductor material is lower than that in the first solvent onto a region of the base material having the liquid composition applied thereto, and removing the second solvent.

Description

BACKGROUND[0001]1. Technical Field[0002]The present invention relates to a manufacturing method of an organic semiconductor film, an organic semiconductor film, a thin film transistor, an active matrix device, an electro-optical device, and an electronic device.[0003]2. Related Art[0004]Recently, as a device which is able to be substituted for a thin film transistor using an inorganic semiconductor material, a thin film transistor using an organic semiconductor material has received attention (for example, refer to JP-A-2004-6782).[0005]The thin film transistor is able to form an organic semiconductor layer by using a liquid phase process in which high temperature and high vacuum are not necessary.[0006]However, in the related art, stability of a solution of the organic semiconductor material which is used in the liquid phase process is low. For this reason, a solid content in the solution is precipitated or aggregated at the time of preservation, and thus an involuntary variation i...

AI Technical Summary

Benefits of technology

[0053]As a method of applying the liquid composition (the composition for an organic semiconductor film) 30′ onto the base material 10, for example, a coating method such as a spin coating method, a casting method, a microgravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, a dip coating method, and a spray coating method, a printing method such as a screen printing method, a flexographic printing method, an offset printing method, an ink jet method, and a micro contact printing method, and the like are included, and one of them or a combination of two or more thereof is able to be used. Among them, from a point of accurately and efficiently forming a fine pattern, an ink jet method is preferable. In addition, in the related art, when a solution (a liquid composition) including an organic semiconductor material is applied by using an ink jet method, nozzle clogging or the like occurs due to precipitation or aggregation of a solid content which occurs at the time of preservation of the solution, and accuracy of an ejection amount or an applying position (an impact position) decreases, and thus an involuntary variation in properties or the like easily occurs in an organic semiconductor film to be manufactured, but according to the invention, even when an ink jet method is used, it is possible to reliably prevent such a problem. That is, when the liquid composition is applied by the ink jet method, the effect of the invention is more remarkably expressed.

[0054]Hereinafter, a constituent of the liquid composition (the composition for an organic semiconductor film) 30′ will be described.

[0055]As described above, in the liquid composition 30′, the organic semiconductor material 31 is dissolved or dispersed in the first solvent 32.

[0056]The organic semiconductor material 31 may be a low molecular material, and it is preferable that the organic semiconductor material 31 is a polymer. Accordingly, it is possible to more effectively prevent a variation in properties between the organic semiconductor films 30 to be manufactured and between portions from occurring, and it is possible to make stability of properties particularly excellent. In addition, when the organic semiconductor material is a polymer, in the related art, the precipitation or the aggregation of the solid content occurs at the time of the preservation of the composition for an organic semiconductor film or the like, and thus an involuntary variation in properties particularly easily occurs in the organic semiconductor film to be manufactured, but according to the invention, even when the organic semiconductor material is a polymer, it is possible to effectively prevent such a problem from occurring. That is, when the organic semiconductor material is a polymer, the effect of the invention is more remarkably expressed.

[0057]When the organic semiconductor material 31 is a polymer, a weight-average molecular weight thereof is preferably greater than or equal to 100 and less than or equal to 10000000, and is more preferably greater than or equal to 1000 and less than or equal to 1000000. Accordingly, it is possible to more effectively prevent a variation in properties between the organic semiconductor films 30 to be manufactured and between the respective portions and to make stability of properties more excellent, and it is possible to make preservation stability or the like of the liquid composition 30′ particularly excellent and to more stably manufacture the organic semiconductor film over a long period of time. Furthermore, the weight-average molecular weight of the organic semiconductor material 31 is able to be obtained by being measured using a Prominence gel permeation chromatography (GPC) system (manufactured by Shimadzu Corporation). The weight-average molecular weight of the organic semiconductor material 31 in examples described later is a value obtained by being measured using such a device.

[0058]As a specific example of the organic semiconductor material 31, for example, polythiophene, polyhexyl thiophene, poly(p-phenylene vinylene), polythienylene vinylene, polyarylamine, a pyrene formaldehyde resin, an ethyl carbazole formaldehyde resin, a fluorene-bithiophene copolymer, a fluorene-arylamine copolymer, derivatives thereof, and the like are included, and one of them or a combination of two or more thereof may be used. By using such a material, the organic semiconductor film 30 to be manufactured has particularly excellent properties such as carrier mobility. In addition, it is possible to more effectively prevent a variation in properties between the organic semiconductor films 30 to be manufactured and between the respective portions, and it is possible to make stability of properties particularly excellent. In addition, in the organic semiconductor material having a thiophene ring, temporal stability at the time of being dissolved in the organic solvent is particularly low, and thus the precipitation or the aggregation of the solid content particularly easily occurs, but according to the invention, it is possible to more reliably prevent such a problem from occurring. That is, when the organic semiconductor material 31 has a thiophene ring in the molecules, the effect of the invention is more remarkably expressed.

Problems solved by technology

However, in the related art, stability of a solution of the organic semiconductor material which is used in the liquid phase process is low.

In particular, when the solution is ejected by using an ink jet method, nozzle clogging remarkably occurs, and thus the problem described above becomes remarkable, and productivity and yield of the organic semiconductor film remarkably decrease.

Images